Frivolous science fiction, you say? Think again. Estimates say that from 5-20% of those who play video games are disabled. Low estimated suggest that 525, 000 disabled users play World of Warcraft. There's a large deaf community that plays, as well as a number with severe physical motor disabilities such as Spinal Muscular Atrophy, as well as smaller visual impairment disorders and learning disorders. A community group called Able Gamers is specifically targeted at disabled gamers, and acts as an advocacy group to gamemakers. One gamer with Multiple Sclerosis who is paralyzed on one side of his body wrote, in a blog, "I feel like blowing things up and killing orcs. That always makes me feel better. Gaming therapy--mmmmmm."
There's a great post with lots of information about disability and gaming and a link to a very moving video of a disabled gamer, Mike Phillips, who has spinal muscular atrophy, playing a game.
And also see: One Thumb to Rule Them All: http://www.youtube.com/watch?v=2BhHwk9qSvl